1. Field of the Invention
The present invention relates to a charged beam processing apparatus, which forms a structure by a direct process using a charged beam, such as an electron beam or an ion beam.
2. Description of the Related Art
Research on CVD (Chemical Vapor Deposition) using a focused electron beam were performed in the 1950s using, e.g., an experiment in which a gas is decomposed in a vacuum, carbon is deposited on an object surface, and the state of a beam shape is inspected. From 1970 to the 1980s, A. N. Broers, Appl. Phys. Lett. 29 (1976), page 596, S. Matsui, K. Mori, J. Vac. Sci. and Technol. B4, (1986) page 299, H. W. P. Koops, R. Weiel, D. P. Kern and T. H. Baum, J. Vac. Sci. and Technol. B6, (1988) page 477, et al., conducted studies on practical applications. Mask formation and tungsten micropattern formation by electron beam CVD, formation of an ultrafine rod having a nanometer size, and formation of a field emitter as a field emission electron source were attempted in those days. Formation of these structures employed a reactive gas, such as WF6, W(CO)6, Mo(CO)6, Fe(CO)6, Me2Au (tfac), or Me2Au (acac) as a precursor. An apparatus used in these application was prepared mainly by adding a gas supply mechanism to an existing electron beam apparatus (Japanese Patent Application Laid-Open No. 5-47636).
Subsequently, research on forming a structure using maskless charged beam CVD technology also progressed using a focused ion beam (FIB) apparatus, in addition to the electron beam apparatus. It was verified that the FIB apparatus can form an arbitrary three-dimensional structure by controlling the beam position of a Ga ion beam highly accurately, based on the design information on the three-dimensional structure (Japanese Patent Application Laid-Open No. 2001-107252 and No. 2004-345009). Also, Furuya, et al. attempted to form a nano-size three-dimensional structure using a high-energy focused electron beam of a transmissive electron microscope by arranging an object to be processed in a magnetic field (Japanese Patent Application Laid-Open No. 2004-244649).
These accomplishments showed that the supply of a precursor gas into a processing chamber and highly accurate control of a focused charged beam enabled not only formation of a comparatively simple structure, such as a wiring pattern or a needle for a field emission type emitter, but also, formation of a nanometer-size three-dimensional structure having a complicated arbitrary shape. The research of this field thus developed greatly.
Although the above fabrication schemes can form a structure for trial and study as they are proven to be able to form an arbitrary shape with a focused charged beam, they have problems in terms of productivity as a practical technique, which can be used to produce a large amount of identical items at a low cost.